Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?

Annotations already indicate read-only, idempotent, non-destructive behavior. The description adds valuable context beyond those: historical depth limited by a 60-day TTL, snapshots only written on cache-miss (so gaps mean no scan), decay computed from daily closes rather than intraday, and detailed response structure. This significantly enhances behavioral understanding without contradiction.

Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.

Is the description appropriately sized, front-loaded, and free of redundancy?

The description is well-structured with clear sections (purpose, args, response, limits) and is front-loaded with the core question it answers. Every sentence adds value, but it is somewhat dense and could potentially be tightened. Still, it remains readable and organized.

Shorter descriptions cost fewer tokens and are easier for agents to parse. Every sentence should earn its place.

Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?

With no output schema, the description thoroughly explains response structure (tracked[], expired[], snapshot_dates[]) and each field's meaning. It also covers limitations (TTL, cache-miss behavior, close-based decay) and why gaps occur. For a telemetry tool with historical dependencies, this is highly complete.

Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.

Does the description clarify parameter syntax, constraints, interactions, or defaults beyond what the schema provides?

Schema description coverage is 100% with clear parameter descriptions. The description adds the concept of 'snapshot family' for the window parameter and clarifies defaults, but mostly restates schema information. While it doesn't add many new details, the family terminology gives additional meaning beyond the schema's simple enumeration.

Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.

Does the description clearly state what the tool does and how it differs from similar tools?

The description clearly states what the tool does: 'Edge persistence and decay telemetry' built from daily snapshots, answering a specific question about how long an edge has existed. This is a specific verb+resource combination that distinguishes it from sibling tools like polymarket_edges, which likely provides current edge calculations.

Agents choose between tools based on descriptions. A clear purpose with a specific verb and resource helps agents select the right tool.

Does the description explain when to use this tool, when not to, or what alternatives exist?

The description provides clear context for when to use this tool: to differentiate between fresh vs. old wide edges and to understand if an edge is shrinking. It doesn't explicitly name alternative tools or provide when-not-to-use guidance, but the intended use case is well implied. The line 'the median lifespan is your competition clock' gives practical context.

Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.